2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle
7 * Copyright (C) 1996 by Paul M. Antoine
8 * Copyright (C) 1999 Silicon Graphics
9 * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
10 * Copyright (C) 2000 MIPS Technologies, Inc.
12 #ifndef _ASM_SWITCH_TO_H
13 #define _ASM_SWITCH_TO_H
15 #include <asm/cpu-features.h>
16 #include <asm/watch.h>
22 * switch_to(n) should switch tasks to task nr n, first
23 * checking that n isn't the current task, in which case it does nothing.
25 extern asmlinkage
void *resume(void *last
, void *next
, void *next_ti
, u32 __usedfpu
);
27 extern unsigned int ll_bit
;
28 extern struct task_struct
*ll_task
;
30 #ifdef CONFIG_MIPS_MT_FPAFF
33 * Handle the scheduler resume end of FPU affinity management. We do this
34 * inline to try to keep the overhead down. If we have been forced to run on
35 * a "CPU" with an FPU because of a previous high level of FP computation,
36 * but did not actually use the FPU during the most recent time-slice (CU1
37 * isn't set), we undo the restriction on cpus_allowed.
39 * We're not calling set_cpus_allowed() here, because we have no need to
40 * force prompt migration - we're already switching the current CPU to a
44 #define __mips_mt_fpaff_switch_to(prev) \
46 struct thread_info *__prev_ti = task_thread_info(prev); \
49 test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) && \
50 (!(KSTK_STATUS(prev) & ST0_CU1))) { \
51 clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND); \
52 prev->cpus_allowed = prev->thread.user_cpus_allowed; \
54 next->thread.emulated_fp = 0; \
58 #define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0)
61 #define __clear_software_ll_bit() \
63 if (!__builtin_constant_p(cpu_has_llsc) || !cpu_has_llsc) \
67 #define switch_to(prev, next, last) \
70 __mips_mt_fpaff_switch_to(prev); \
73 __clear_software_ll_bit(); \
74 __usedfpu = test_and_clear_tsk_thread_flag(prev, TIF_USEDFPU); \
75 (last) = resume(prev, next, task_thread_info(next), __usedfpu); \
78 #define finish_arch_switch(prev) \
81 __restore_dsp(current); \
82 if (cpu_has_userlocal) \
83 write_c0_userlocal(current_thread_info()->tp_value); \
87 #endif /* _ASM_SWITCH_TO_H */